Drive system for clothes dryers



- June 3, 1969 DRIVE SYSTEM FOR CLOTHES DRYERS Filed Jan. 12, 1968 R. D.TRIPLETT ET AL Sheet 23" 1 e22z 0r9 Faber! j Dip/eff, Zea 7/3110)? and71227] J [0116 a/lkcw 0w June 3, 1969 p g -r ET AL 3,447,248

DRIVE SYSTEM FOR CLOTHES DRYERS Filed Jan. 12, 1968 Sheet of 5 June 3,1969 TR|PLETT ET AL 3,447,248

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June 3, 1969 [1v TmpLETT ET AL 3,447,248

DRIVE SYSTEM FOR CLOTHES DRYERS Filed Jan. 12 1968 Sheet 5 of s J g; 6 Za7 71 C 75 86 g 89 75a 72 United States Patent 3,447,248 DRIVE SYSTEMFOR CLOTHES DRYERS Robert D. Triplett, Leo V. Buck, and Terry J. Laue,Etfingham, 11]., assignors, by mesne assignments, to Fedders(Forporation, a corporation of New York Filed Jan. 12, 1968, Ser. No.697,453 Int. Cl. F26]: 11/02, 11/18 US. Cl. 34139 7 Claims ABSTRACT OFTHE DISCLOSURE This invention relates to clothes dryers and moreparticularly to clothes dryer drive systems.

In clothes dryers of the type including a clothes contamer or basket,the basket is rotatable around a generally horizontal axis by a singlecontinuous belt extendmg around the basket and a drive pulley connectedto one end of a shaft of a motor, the dryer also includes anair-circulating fan rotatable about the basket axis and having a pulleyconnected by a belt to a pulley on the other end of the motor shaft. Insuch drive arrangement, it is necessary to provide tension on the drivebelts to compensate for load variations and for slack in the belts.

An object of the present invention is to improve clothes dryer basketand fan drive systems of the type including a motor having its driveshaft provided with pulleys for belts respectively surrounding thebasket and a fan-drive pulley by the provision of improved means formounting and biasing the belt drives to provide a self-energizing actionoperable to effectively and continuously compensate for changes in thedriven load and for slack built up in the belts.

A further object of the present invention is to improve clothes dryerbasket and fan drive systems of the type including a motor having itsdrive shaft provided with pulleys for belts respectively surrounding thebasket and a fan-drive pulley by the provision of common mounting meanspivotally supporting the motor and also a compensating idler pulleyarrangement for biasing the belts to prevent slip between the belts andthe drive pulleys.

A further object of the present invention is to improve clothes dryerbasket and fan drive systems of the type wherein a single continuousdrive belt is passed in driving engagement over the outer periphery ofthe basket and an idler pulley assembly, and a belt is engaged with afandrive pulley, the belts being driven by pulleys on a motor shaft, theimprovement residing in the provision of a belt slack-compensatingsystem including a bracket having a support pivotally mounting the motorand the idler pulley assembly, and the idler pulley assembly having arocker arm pivoted on the support and biased by a: tension spring tohold the idler pulley against the basket drive belt.

Additional objects, features and advantages of the invention disclosedherein will be apparent to persons skilled in the art after theconstruction and operation are understood from the following descriptiontaken in conjunction with the accompanying drawings in which:

FIGURE 1 is a vertical sectional view of a clothes dryer embodying theinvention, and taken along the plane of the line 1-1 of FIGURE 2;

Patented June 3, 1969 FIGURE 2 is a front elevational view of the dryershown in FIGURE 1, the front panel being removed and certain partsbroken away and partly sectionalized to illustrate details of the dryer;

FIGURE 3 is a perspective view of the dryer, with the basket removed tomore clearly illustrate details of the fan drive and air circulationarrangement;

FIGURES 4 and 5 are respectively enlarged front and side views of one ofthe basket front supports; and

FIGURE 6 is an enlarged vertical sectional view of the basket rearsupport and fan mounting assemblies;

FIGURE 7 is a top plan view of the basket and fan drive mechanismsincluding a one-way clutch and pulley assembly of the basket drivemechanism;

FIGURE 8 is a sectional view of the one-way clutch and pulley assembly,taken on line 8--'8 of FIGURE 7;

FIGURE 9 is a perspective view of the one-way clutch;

FIGURE 10 is a sectional view of the clutch and pulley assembly, takenon line 1010 of FIGURE 8;

FIGURE 11 is a perspective view of the cabinet.

Referring now to the drawings, the domestic clothes dryer is providedwith a cabinet generally indicated at 10 having spaced side walls 11 and12; a rear wall 13; top and bottom walls 14 and 15; and a front wall 16.The front wall 16 has a door 17 hinged thereto and closing an opening,defined by a cylindrical flange 18, in the front wall 16, providingaccess to the front opening 19 of a rotatable clothes container orbasket 20 for loading and unloading clothes in the basket.

The basket is mounted for rotation about a substantially non-verticalaxis which, in the present case, is preferably horizontal. Moreparticularly, the basket is substantially cylindrical in shape, having acylindrical wall 21; a front wall 22 having the opening 19 receiving theflange 18 of the cabinet front wall 16; and a rear wall 23 having ashaft and bearing assembly 24 for the basket 20 and a fan or blower 25.The basket is supported at its front end by spaced supports or skids 26,26 mounted on the cabinet bottom wall 15 and having arcuate uppersurfaces conforming to the curvature of the cylindrical wall 21 andprovided with shoes 27, 27 of suitable hearing material engaging thebasket. The rear end of the basket is supported by the shaft and bearingassembly 24 and, as seen in FIGURES 1 and 6, the basket rear wall 23 hasconically-shaped depressed portion 29 providing a mounting means in theform of a sheet-metal hub 30 secured thereto as by welding and which hubreceives a ball-like bearing 31 secured to a shaft 32 extendingrearwardly through a hollow cylindrical portion 33 of a pulley 34 andinto a supporting bracket 35 fixed to the rear wall of the cabinet bybolt and nut assemblies 36 as shown in FIGURE 6. The shaft 32 is fixedby pins 28 to the radially-inwardly extending cylindrical portion 37 ofbracket 35.

The 'blower or fan assembly 25 comprises a circular sheet-metal plate 38having cut-out portions to define a plurality of radially-extendingblades 39 each twisted from the plane of the plate, as shown in FIGURES1 and 6. Referring to FIGURE 6, the plate 38 is secured at its center tothe pulley 34 rotatably mounted on spaced bearings 40, 40 on shaft 32.The fan is confined between and enclosed by basket rear wall 23particularly the conical portion 29 thereof and the front plate 41 of aduct assembly 42, the rear plate 43 of the duct assembly being spacedfrom the front plate 41 to provide a passage A therewith. The plate 43is connected to bosses 44 (FIG- URES 1 and 11) formed in and projectingfrom the cabinet rear wall to provide passages B for the inflow ofambient air by the fan from vents '45 in the cabinet rear wall andthrough a plurality of circumferentially and radially spaced openings 46in the basket rear wall and into the basket interior. As seen in FIGURES1 and 3, the outer edge of the duct plate 41 is inwardly bent to providea cylindrical flange 47 for mounting an annular felt seal 48 fixedthereto by a band 49, the seal engaging the basket rear wall to confinethe air between the basket rear wall and the plate 41 for flow into andthrough the openings 46 in the basket rear wall. The air flows throughthe basket, and also the openings 50 in an upper collector duct assembly51 secured to the front walls of the cabinet and providing a passage forflow of air from the basket through a removable lint screen or trap 52supported in the duct. As seen in FIGURES 1 and 2, the duct assembly 51is a rectangular shaped boxlike structure having front and rear walls53, 54; side walls 55; and top and bottom walls 56 and 57, the frontwall 53 being secured to the cabinet front wall, and the rear wall 54having the openings '50 defined by an arcuate flange 58 and engaging anannular seal 59 mounted on the cylindrical portion 19 of basket definingthe clothes-receiving opening of the basket. The rear wall 54 has itslower portion provided with a flange 61 forming a ledge for supportingthe lint screen 52 which is disposed with respect to the duct walls soas to filter lint in the air flowing from the basket through the ductassembly 51.

The air-circulation system further includes a second duct assembly 62including a cylindrical conduit 63 connected to a funnel-shaped member64 having a rectangular end receiving a complementary-shaped portion 65,defining the bottom opening of the duct assembly 50. The conduit 63extends through the rear wall 13 of the cabinet and is connected, inconventional manner, to a standard vent or flue pipe for conducting themoistureladen exhaust to the outside of the house.

While ambient air is drawn into the dryer by the fan through the cabinetrear wall, an air heating assembly 66 comprising, in general, acylindrical housing 67, which may contain either a conventionalelectrically-energized heater 68, as shown, or gas-fired heating means,is elfective to heat air drawn into and circulated through the housing67 by the operation of the fan.

The heating assembly 66 is supported on a pedestal P mounted on thebottom Wall 15 of the cabinet. The housing 67 extends rearwardly and isconnected to a triangular-shaped housing 70 (FIGURE 3) forming portionsof, and connected to, the front and rear plates 41 and 43 of the ductassembly 42, so that the fan is efiective to draw heated air in housing67 and through housing 70 into the passage A for mixture of the heatedair with the exterior ambient air drawn through passages B, the airmixture being forced into the basket through the openings '46 in thebasket rear wall 29.

The present invention is directed to the improved belt drive system forthe basket and fan and incorporating means for providing aself-energizing action to insure constant tension on the belts bycompensating for load variations and for slack in the 'belts. Moreparticularly and referring to FIGURES l, 2, 3, 7 and 8, the belt drivesystem is generally indicated at 71 and comprises a bracket 72 having abottom wall 73 secured, as by welding; to the cabinet bottom wall 15;spaced side walls 74 and 75; and a wall 76 extending between andconnecting the side walls and merging with the bottom wall. The bracket72 has aligned openings in the upper offset ends 74a and 75a of the sidewalls 74 and 75 receiving pivot members 77 fixed to and projectingoutwardly of an inverted U-shaped motor support 78.

The side walls 79 and 80 of the support 78 have their lower ends formedto provide downwardly facing arcuate recesses receiving rubber bushings81, 81 mounting hubs projecting laterally from the casing 82 of areversible motor M. The bottom ends of each arcuate recess is defined byoppositely extending lubs 83, 83 projecting into slots at each end of anarcuately curved spring retainer or clip 84, the retainers 84 extendingunder and engaging the motor hub bushings 81, 81 and holding the motoron the support 78. The motor drive shaft 85 extends outwardly of the hubbushings 81, 81 on opposite .4 sides of the motor and have connectedthereto drive pulleys 86, 87. It may be noted that L-shaped retainerclamps C are bolted to the side walls 74 and 75 of the motor bracket 72and bear against the ofiset ends 74a and 75a of the walls to preventspreading of the walls and detachment of the motor from the bracket.

As shown in FIGURES 1 and 2, a V-belt 88 surrounds and passes around andengages substantially the outer diameter of the basket and is driven bythe pulley 86 to rotate the basket. A V-belt 89 is mounted on the drivepulleys 34 and 87 and is operative to rotate the fan or blower 25. Anidler pulley 90 engages belt 88 and is rotatably mounted on a bifurcatedportion 91 of an arm 92 of a lever 93, the lever being pivotallysupported, intermediate its ends, on the motor support side wall 79 by abolt and nut assembly 94. The lever has the end of its other armprovided with a slot receiving one end of a tension spring 96, theopposite end of the spring engaging a hook member 97 fixed to the sidewall 74 of the bracket 72. The tension spring is light and low-rate.

In the operation of the improved basket and fan drive assembly, rotationof the motor drive shaft in a direction to rotate the pulleys 86 and 87causes the pulley 86 to activate the belt 88 to drive the basket totumble the clothes in the basket, while the pulley 87 activates belt 89to drive the fan to circulate air through the basket and dryer asindicated by the arrows in FIGURE 1. The degree of frictional engagementof the belts with the basket and pulleys is determined by the weight ofthe motor and its point of pivoted connection to the support bnacket 72,as well as by the force exerted by tension spring 96 on the lever 93 andthereby, through its idler pulley 90, on the belt 88.

In tumbling basket drive arrangements wherein a continuous drive beltpasses around the periphery of the basket, a problem exists because thesubstantial length of the belt can produce relatively great slackfollowing periods of operation that requires continuous compensation tomaintain a desired driving engagement of the belt with its drive pulley.For this purpose, to avoid slip between the pulley and the belt, it isnecessary to maintain the belt to be wrapped around the drive pulleythrough substantially as shown in FIGURE 2. In the illustratedarrangement, the lever 93 is pivoted centrally thereof on the motorsupport 78 to provide a bellcrank having the arms 92 and 95 offset withrespect to each other at a predetermined angle to cause the tensionspring 96 to bias the idler pulley 90 upwardly toward the basket in anarc to continuously bias the belt 88 into driving engagement with thepulley 86 and substantially continuously about the pulley 86 through awrap of approximately 180 to prevent any undesired slip between the belt88 and pulley 86.

Accordingly, the idler assembly is efiective to continuously compensatefor changes in the driven load within the rotating basket by the tensionspring 96 acting through the lever 93 to maintain a desired tension onthe belt 88 irrespective of the load. In the event slack should developin the belt 88, the desired wrap of belt around the pulley 86 iscontinued because the idler pulley -90 will be biased to provide thedesired driving engagement between the belt and pulley 86.

In the present embodiment of the invention, it will be noted that thedrive motor is provided with the pulleys 86 and 87 on its drive shaftfor simultaneously effecting operation of the belt 88 to drive thebasket and operation of belt 89 to drive the pulley 34 to rotate thefan. Accordingly, it is necessary to insure optimum drive by providingmeans, not only to compensate for slack in the basket drive belt, butalso for slack in the fan drive belt. For this purpose, the idlerassembly is mounted on the motor support 78 and the motor support ispivoted at 77 to permit arcuate movement of the motor M in a downwarddirection to cause the weight of the motor to bear, through the motordrive shaft pulleys 86 and 87, on the basket and fan drive belts '88 and89 and effectively provide constant tension on the belts 88 and 89. Asboth belts must be substantially slack-free to insure optimum drivingengagement with the pulleys during initial operation, and particularlyfollowing periods of operation, the pivotal mounting of the motorinsures constant driving engagement of both belts with their drive anddriven pulleys, when supplemented by the idler assembly slack-adjustmentof the belts. In this respect, the fan drive belt 89 is first assembledwith the pulleys 34 and 87 and the weight of the motor effects drivingengagement of the belt with the pulleys. Thereafter, the belt 88,surrounding the basket, is engaged with the pulley 86 and with the idlerpulley 90, the weight of the motor and spring 96 causing the belt tofirmly engage the basket, drive pulley 86 and idler pulley 90. Thisarrangement provides for the slack-adjustment for both belts in the formof a selfenergizing effect of the belt pick-up system in which the belt89 to the fans initially pick up and then the belt 88 to the basket sothat constant tension is continuously applied to both belts to preventslip between the motor drive and fan pulleys, basket, and belts bycompensating for belt slack.

More particularly and referring to FIGURE 2 for an analysis of thevector forces, forces on V-belt 89 are a resultant of the following: theweight of the motor M produces a counterclockwise moment about pivotmember 77 which is assisted by counterclockwise moment vectors fromslack side tension of belt 88 and tension spring 96 about pivot member77. The sum of these moments is partially reduced by the clockwisemoment of the tight side tension of belt 88 around pivot member 77. Theresultant sum of these vectors provides the tension necessary for V-belt89 to drive without slip. Advantages of this drive system are that, onstarting up, when the wedging action of the belts forces for motor toclimb the belts, and rotate about pivot member 77 in a clockwisedirection, the motor moment vector, and the spring moment vector aboutpivot member 77 are increased and apply an increased force on belt 88preventing any tendency to slip, which slip tendency is characteristicon startup of other systems, and, for this reason, our new drive systemcan be referred to as self-energizing.

Control means for the clothes dryer basket and blower systems arecapable of selectively providing for simultaneous rotation of the basketand blower for normal clothes-drying, or rotation of the fan only whilethe basket is stationary to permit static drying of the clothes. Moreparticularly, a reversible motor driving the blower in both directionsof rotation of the motor shaft, and an automatically-operable one-wayclutch drivingly connects the reversible motor, during rotation of themotor shaft in one direction, to the basket for normal clothes-drying;rotation of the motor shaft in the opposite direction disengaging theclutch to cause the drive to the basket to be disconnected, while thedrive to the blower remains operative for static drying of the clothes.

Referring to FIGURE 8, a one-way clutch and bearing assembly 98surrounds the motor drive shaft 85 and is positioned within acylindrical housing 99 formed integral with the pulley 86. The assembly98 comprises a unitary shell body 100 of sheet metal of generallycylindrical shape having a uniform external diameter with radiallyinwardly directed annular end flanges 101 and 102. Within opposite endsof the body 100 are disposed the retainers 103 and 104 each having slotsfor receiving axially spaced sets of roller bearings 105, 106 engagingspaced sets of cylindrical raceway surfaces 107, 108 of the motor shaft85 and body 100. Between the spaced sets of raceway surfaces 107 and108, the body 100 is formed to provide a clutch portion 109 having wedgeor cam faces 110. These cam faces form spaces between which clutchrollers 111 are received. A molded plastic retainer 112 provides aone-piece actuation cage for the rollers 111 to maintain the rollers 111in operative relation to the cam faces 110 and surface of shaft 85. Asseen in FIGURE 10, the cage 112 is provided with roller-receivingopenings circumferentially spaced about the shaft and defined by bars113. In each opening, the cage is formed to provide a thin reed typeleaf spring 114, each spring having a juncture with a bar face fromwhich it projects at a slight angle in opposite directions away from thebar and towards and almost to the ends of the openings in the cage. Theroller bearing and one-way clutch assembly 98 is frictionally fittedbetween the cylindrical surfaces of the coaxial shaft 85 and pulleyhousing 99.

As shown in FIGURE 10, the clutch rollers 111 are frictionally incontact with the shaft 85 and wedge faces 110 of the clutch portion 109of the shell body 100. Rotation of the motor shaft 85 in acounterclockwise direction, as shown by the arrow, causes wedging actionof the rollers 111 between the shaft 85 and cam faces 110 therebyforcing the pulley housing 99 to rotate in the same direction as theshaft so that the shaft rotates with the housing. The wedging actionalso presses the outer member of shell body tighter against the housing99 resulting in more frictional force against relative rotation orslippage occur. ring between the shaft 85 and housing 99. As the motoris wired for bi-directional rotation, a suitable selector switch, suchas a triple-pole, double-throw switch, may be provided to control themotor to rotate the motor shaft in opposite directions. When the switchis effective to obtain rotation of the motor shaft in a clockwisedirection, the wedging pressure between the shaft 85, rollers 111, andthe housing 99 will be released to allow the shaft to slip under therollers and overrun the housing 99 effectively disconnecting the drivebetween the motor shaft and the pulley 88 and thereby the drive betweenthe motor and the basket. (For a more complete description of theone-way clutch and roller bearing assembly, reference may be made to US.Patents 3,184,020 and 3,194,368).

While in accordance with the patent statutes the improved belt drivesystem has been described in what at present is considered to be thepreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is therefore aimedin the appended claims to cover all such equivalent variations as fallwithin the true spirit and scope of the invention.

What is claimed is:

1. In a domestic dryer, a casing including a base; a cylindricalcontainer in said casing; support means fixed to said base and mountingsaid container for rotation about a substantially non-vertical axis; afan adjacent said container and having a shaft mounted on said supportmeans for rotation of said fan, relative to said container, about saidaxis; a motor having a drive shaft with its ends extending outwardly ofsaid motor; a bracket secured to said base; a carrier for said motor,said motor shaft having its ends projecting from said carrier; first andsecond pulleys fixed on the ends of said motor shaft; a third pulleyfixed to said fan shaft; a first continuous belt surrounding andengaging the outer periphery of said container and said first pulley; asecond continuous belt connecting said second and third pulleys forrotating said fan; and means for mounting said motor carrier on saidbracket for pivotal movement of said carrier about a predetermined axisto engage said first and second pulleys with said belts; and an idlerassembly including a pulley engaging said first belt, a lever pivotallymounted on said carrier and supporting said idler pulley adjacent saidfirst pulley, and a tension spring connected to said lever and to saidbracket and operable to maintain said idler pulley in engagement withsaid first belt.

2. In a domestic dryer as defined in claim 1 wherein said motor ispositioned on said carrier between the pivotal connection of saidcarrier to said bracket and the pivotal connection of said lever to saidcarrier.

3. In a domestic dryer as defined in claim 1 wherein the weight of saidmotor is effective to provide tension on said second belt to compensatefor slack during its operation; and said idler assembly operates to biasthe idler pulley along a predetermined arc to maintain said first beltwrapped about said first pulley through approximately 180 duringcompensation by said idler assembly of slack in said first belt.

4. In a domestic dryer as defined in claim 1 wherein said lever is abellcrank pivotally mounted centrally thereof on said carrier in spacedrelation to said pivotal connection of said carrier to said bracket, andincludes first and second arms with said idler pulley rotatably securedto said first arm to position said idler pulley adjacent said firstpulley, and said tension spring being connected to said second arm.

5. In a domestic dryer as defined in claim 4 wherein said lever has itssecond arm extending downwardly, from the pivotal mounting of said leveron said carrier, for connection to said tension spring; and said tensionspring extends substantially horizontally between said lever second armand said bracket.

6. In a domestic dryer as defined in claim 1 wherein said carriercomprises a U-shaped member having spaced side walls supporting saidmotor with the motor shaft ends extending outwardly of said walls, saidcarrier side walls being connected to said bracket for pivotal movementof said carrier and thereby said motor about an axis ofiset from saidshaft to maintain said first and second pulleys in engagement with saidbelts.

7. A domestic dryer as defined in claim 6 wherein said lever is abellcrank pivotally mounted on one of said side walls in spaced relationto said pivotal connection of said motor carrier to said bracket.

References Cited UNITED STATES PATENTS 3,320,683 5/1967 Worst 34-1392,830,385 4/1958 Smith 34133 2,996,809 8/1961 Shapter 34-133 XR3,330,049 7/1967 Helton 34-139 3,339,423 9/1967 Bergeson 34133 XRKENNETH \V. SPRAGUE, Primary Examiner.

